The murder of Hell's Angel Gerry Tobin brought the shadowy world of biker gangs into sharp focus for police and forced them to get a grip on the threat they posed.

The marksman’s shot which claimed the life of Mr Tobin was the latest chapter in a bitter story of hatred between the Outlaws and the Hell’s Angels.

The shooting - thought to have been sanctioned by overseas “overlords” in retaliation for a previous incident - took place on territory which the Outlaws regard as their own.

Many Outlaws are said to regard the location of the Hell’s Angels’ annual Bulldog Bash - Long Marston, near Stratford-upon-Avon - as a “deliberately provocative” venue chosen to inspire conflict.

Detective Constable Steve Cox, who gave evidence during the Tobin murder trial, has followed the activities of biker gangs for many years and has established that the Outlaws view their heartlands as Warwickshire, Staffordshire, south Wales, Derbyshire, Birmingham and London.

While the Hell’s Angels also have a presence in London and south Wales, they regard areas including Windsor, Kent, Essex and Wolverhampton as their strongholds.

“Long Marston would be considered in the territory of the Outlaws. The south Warwickshire chapter would see that area as under their jurisdiction,” Det Con Cox said.

The rivalry between the two gangs originated in a series of brutal murders in north America in the late 1960s and has since spread to other parts of the world.

Police believe the murder of Gerry Tobin might have been carried out in retaliation for another attack elsewhere in the world.

Detective Superintendent Ken Lawrence, who led the Warwickshire Police murder inquiry, said: “I don’t think they would take on something like this without sanction because of the repercussions. There would have to be some awareness and sanction.”

The international dimension of the intense and mutual hatred which resulted in Mr Tobin being murdered has its roots in the late 1960s when an American member of the Outlaws raped the wife of a Hell’s Angel.

According to papers presented to a council licensing committee prior to last summer’s Bulldog Bash, the gang rivalry escalated into a vicious cycle of revenge which ended with three Hell’s Angels being murdered and their bodies thrown into a Florida quarry.

Since those events, according to officers tasked with combating biker violence, the ingrained antipathy between the two gangs has simply become more entrenched.

During its attempts to convince Stratford-upon-Avon’s licensing authority that the Bulldog Bash posed a danger to public safety, Warwickshire Police detailed a number of incidents, including the 2001 shooting of a Hell’s Angel on the M40 which mirrored the murder of Mr Tobin.

In its statement, the force said: “In order to appreciate the potentially life-threatening risk to members of the public as a result of the Bulldog Bash, it is necessary to understand the history of the motorcycle clubs.

“In 1998, the Outlaws made a specific threat to bomb the Bulldog Bash. This threat was taken seriously by both the police and the event organisers. On August 12, 2001, a Hell’s Angel member was shot on the M40 as they left the Bulldog Bash. This was treated as an attempted murder.

“The circumstances were almost identical to the murder of Gerard Tobin last year. The individual was shot three times in the leg.”

On that occasion the shots were believed to have been fired from a dark-coloured saloon car, although the injured party refused to make a formal complaint.

In their submission, Warwickshire Police also cited numerous examples of violence between the two gangs across Europe and north America, including a 2006 murder in New Hampshire in which an Outlaws “security chief” killed a man who was wearing a Hell’s Angels shirt. But, while the depth of the rivalry is clear, the exact reason for Mr Tobin’s murder remains a mystery due to the “shroud of secrecy” surrounding biker gangs.

“They do not talk to us, as witnesses and victims, they do not talk to us so sometimes we do not know what is really going on,” Mr Lawrence said. “It’s difficult to link it (the shooting) to a previous particular incident.

“There were other events last year in August around the same time he was murdered, one in Sweden and North America. I do not know what this was linked to. It’s very difficult to link one attack to another because they are going on all the time.”

Mr Lawrence believes it is likely that the South Warwickshire chapter of the Outlaws was chosen to carry out the killing by those higher up in the organisation because the Bulldog Bash, organised by the Hell’s Angels, was on their “turf”.

The Outlaws organisation was founded in the US in 1935 and has about 200 chapters across the globe.